The fuel gauge is sometimes jumping like mad from zero to the fuel range.
It is jumping each second or less...then after a while it might be quiet and indicate the fuel range. Then it goes back to jumping mode.
Jumping is more likely with low fuel levels.
Another thing is that fuel levels change dramatically when I pull the brakes or accelerate...it is no where near precise.

I hoped I could find the reason for a loose contact for the fuel gauge in the cluster while I had it was out...I cleaned contacts but no improvement.
Is the reason in the tank...bad sender unit?
How can I get access to this unit and is there a way to clean?
Also the reserve light is not working...can't be the light bulb in the cluster.

I pulled the sender unit. Access is from the trunk under the white plastic cover in the middle. It is easy to undo. Pull the 3 connector plug, take the 5 nuts off and pull the tube. When you have the unit in hand you can undo the bottom small nut, take off the big washer and then unscrew the plastic labyrinth. Mine was full of crab.
Then slide the aluminum tube down and you see the entire sensitive mechanism.
My unit was a bit corroded and dirty. Be careful with the 3 fine wires. My tube had a crack...so the condition was clearly not new. I just cleaned everything and I put it right back. The crack is probably the reason why the labyrinth has no effect in retarding any level changes during accelerating or braking...
I guess long term I 'd need a new unit.
Martin
The crazy jumping stopped now...which is good. I doubt that I could bring the reserve light back to life but I am happy with the first step

Hmmm, I think maybe you should not park in the harbor.

I'm guessing you are using, "Shell" gasoline?

Okay, enough of the stupid responses.

The reserve light is triggered by a set of points making contact. One is on the float and the other is on the sender's framework. It's not unusual for them to form a layer preventing continuity. They are easy to clean.

Does the reserve light work with the sender out of the tank and turned upside down?

Hi Mike,

I did briefly clean the 2 reserve contact point on the fixed bottom part but not successfully. The moveable plate part looked good. I didn't measure continuity though... It is relatively easy to remove and I thought going step by step.
The aluminum tube has a crack at the bottom and this might cause a short regarding gas flow...and therefore the gauge is moving a lot during braking and acceleration.
In a second round I will try and start some more measuring and testing.
I am sure the 3 connectors can be tested with continuity and resistance.
Any values for testing purposes?

Martin

I've never ohmed them out. I usually just tilt the sender when I have it removed to check for fuel gauge changes.

What seems to work no is the general fuel level. i believe the level is accurately shown.

Two things obviously don't work on my unit:
1) reserve light
2) fast gauge changes during/after acceleration and braking

Number 1) I need to find out if it is a sender problem or ...there is slight chance in theory that the light bulb gave up (the one I tested positive last week). I'll try and test with the meter checking continuity if I find the pin for reserve. If I can find continuity
at very low fuel levels....then it must be the bulb in the cluster (or a broken cable in between).
Number 2) I think I know the reason for relatively fast gauge changes: fuel finds some shortcut not going through the labyrinth and thus flowing in and out the unit too fast.

Martin